Amazon has been getting a lot of press lately with the new version of the Kindle. If you don't mind reading books on your iPhone screen -- which is much smaller, but has color, more contrast, a much brighter screen and is back-lit so you can read in a dark room -- Amazon has released Kindle for iPhone, a free app that allows you to read any of the hundreds of thousands of books available at the Amazon Kindle Store on your iPhone. You can't actually buy a book using the iPhone app, but you can use Safari on your iPhone to access the Amazon Kindle Store website (the app itself even gives you a link that opens up Safari).
There are lots of free public domain books for the Kindle if you want to download the free app and get a feel for what it is like. Here is a a link to free books in the Kindle Store that can get you started.
Once you buy a book, when you start the Kindle for iPhone app any books you purchased are listed. Just tap a book to start reading it.
The books appear full screen, and you can swipe your finger left or right to go through the book page by page. Or, you can tap once on the screen to pull up an overlay with buttons to do things like add a bookmark (the plus sign), go to a specific section of the book, or increase or decrease the font.
If you own a Kindle, you can use technology that Amazon calls Whispersync to switch back and forth between your Kindle and your iPhone. Both devices remember your bookmarks and remember where you stopped reading, so you can pick up reading again on either device.
I don't own a Kindle, but I've always been intrigued by it. The Kindle for iPhone app will be a nice way to get a feel for what it is like to read digital books. I wonder whether reading a long book on my iPhone screen would start to strain my eyes after a while, but as you can see from the screenshots above, the font looks like it would be quite easy to read for an extended period of time. We'll see.
[UPDATE: Good sources for more information on this app include articles posted today by Harry McCracken (Technologizer), Glenn Fleishman (TidBITS), Brad Stone (New York Times), Jeremy Horwitz (iLounge) and Nicole Lee (CNET). I've seen conflicting reports on whether this app will eventually handle newspapers or other sources besides books; right now, the app just handles books. I've also seen conflicting reports on whether the text in books can use hyphens to better fit the iPhone screen; McCracken says no but Fleishman says yes, and both use pictures to back up their positions.]